Suffocation inhibiting inhalator-exhalator valve



May 7, 1963 A. BLOOM 3,088,477 SUFFOCATION INHIBITING INHALATOREXHALATORVALVE Filed March 28, 1961 2 Sheets-Sheet 1 19 S [I I ig w l4 7 Zo l 5731 57 4s ses5 30 a r I y 1 3' AARON BLOOM INVENTOR.

ATTORNEY y 7, 1963 A. BLOOM 3,088,477

SUFFOCATION INHIBITING INHALATOR-EXHALATOR VALVE Filed March 28, 1961 2Sheets-Sheet 2 e8 71 S 76 '79 E T 9 g 86 J v I 85 i i I 84- i 75 92 95 Ii I as I i AA RON BL 00M IN VEN TOR.

ATTORN EY 3,088,477 SUFFOCATlON INHIBETING INHALATOR- EXHALATOR VALVEAaron Bloom, Pasadena, Calif, assignor to Sierra Engineering Company,Sierra Madre, Calif, a corporation of California Filed Mar. 28, 1961,Ser. No. 98,880 3 Claims. (Ql. 137-64) The invention relates tobreathing valves of the type used on respiratory apparatus and moreparticularly is concerned with a valve which admits air or oxygen from asource of supply to a breathing mask and which shuts otf the supply whenthe user exhales through the valve, permitting the exhaled gases toescape. More particularly, the valve is one designed inherently in suchfashion as to inhibit suffocation in the event that the oxygen or gassupply becomes shut off or depleted.

Among the various valves heretofore designed for supplying oxygen to abreathing mask, sundry safeguards have been incorporated which for themost part have necessitated adding various accessories to what wouldotherwise be a relatively simplified valve construction. Despite t-hecomplicating of these valves to such a degree, the safeguards have,however, been worthy of inclusion and sufficient to warrant thedeparture from simplification. One contingency, however, has as yet notbeen adequately provided against, especially with a simple valve typestructure which works smoothly and which gives adequate insur-ance,namely, the possibility of suffocation or semisuffocation of a personusing an oxygen or air supply under conditions where the ambient air ofthe locale in which the user is situated contains at least some oxygenand where the supply of oxygen or air becomes inadvertently cut off ordepleted. Under those circumstances with the mask still in place, thevalving ordinarily becomes obstructed and particularly the exhalationvalving so that, although the user can exhale, he becomes unable toinhale through the exhalation valve and therefore suffers because the-reis no air or oxygen supplied through the inhalation valve due todepletion.

It is therefore among the objects of the invention to provide a new andimproved combination inhalator-exhalator valve device which is soconstructed inherently that it is capable of inhibiting suffocation inthe event of a cut off or depletion of the oxygen or air supply. Anotherobject of the invention is to provide a new and improved combinationinhalator-exhalator valve device constructed in a simple fashion by arearrangement of the proportions of surfaces of a moving valve elementsubjected to inhalation and exhalation pressures such that when thepressure condition within the valve is changed during inhalation cycleunder circumstances where there is a depletion of supply, the exhalationvalve will open and simultaneously permit the user to inhale ambient airthrough the exhalation valve, thereby to fill his lungs to the fullvolume before exhaling and accordingly inhibit suffocation.

Another object of the invention is to provide a new and improvedcombination inhalator-exhalator valve device which is of speciallysimplified construction and so constructed that the action of themovable valve elements is dampened or cushioned by regular oxygen or airpres sures within it, thereby to prevent chatter and flutter, especiallyunder circumstances where the breathing is rapid and accordingly improvethe reliability and dependability of performance under a wide variety ofcircumstances.

Still another object of the invention is to provide a new and improvedcombination inhalator-exhalator valve device which makes use of aplurality of flexible elements interconnecting sundry moving parts of acomposite valve 3,088,477 Patented May 7, 1963 element, thereby addingconsiderable flexibility to the action of the moving valve element whileat the same time keeping it dependably centered with respect to theseat.

Also included among the objects of the invention is to provide a new andimproved combination inhalator-exhalator valve, the construction ofwhich permits critical parts to be made separately to exceptionallyclose tolerances and thereafter assembled by an easy assembly operationinto a unitary valve device which, while inexpensive, is alsodependable.

This application is a continuation-impart of copending applicationSerial No. 801,591, filed March 24, 1959 and now Patent a t-3,035,594.

With these and other objects in view, the invention consists in theconstruction, arrangement and combination of the various parts of thedevice, whereby the objects contemplated are attained, as hereinafterset forth, pointed out in the appended claims and illustrated in theaccompanying drawings.

In the drawings:

FIGURE 1 is a longitudinal sectional view of one form of the valvedevice which incorporates as a feature hose pull protection.

FIGURE 2 is an end elevational View of the device of FIGURE 1 partiallycut away.

FIGURE 3 is a longitudinal sectional view of a modified form of thedevice wherein the structure of the composite movable valve portions hasbeen modified.

In an embodiment of the invention chosen for the purpose of illustrationthere is shown a combination inhalator-exhalator valve device whichcomprises a composite body consisting in the main of three elements,namely, a base or supply end member 10, a cap or mask end member 11, anda spacer 12. On the base is a neck 13 provided with a bead 14 forattaching and securing a length of supply hose l5 thereto. Within theneck is a supply passage 16 which communicates with the interior 17 ofthe supply hose on one side and a supply chamber 18 on the oppositeside.

The cap 11 is provided with a connection 19 by means of which the valvecan be attached to a breathing mask (not shown). A spider 20 serves toreinforce the structure of the cap adjacent a passage 21 by means ofwhich air passes between the mask and an exhalation chamber 22.

The spacer 12 is an annular sleeve-like element consisting of a portion23- attached to an annular flange 24 of the base and an extension 25serving to space the portion 23 from the cap to provide exhalation ports26, one of which is shown in FIGURE 1. The parts are held together byscrews 27, as shown in FIGURE 1, wherein the screw extends through theflange 24, the portion 23, and extension 2 5 into a flange 28 on thecap. When these portions are connected together as shown, they form inessence the valve body comprising the rigid portion of the structure.

Within the base is a guide ring 34) spaced inwardly from the flange 24,leaving an annular space 32, therebetween. guide ring 3i). The interiorof the combination valve consists in the main of a relatively compositeaxially shiftable sleeve indicated generally by the reference character33 which mounts an inflow check valve 34 and an exhalation check valve35.

The inflow check valve 34 is one wherein the valve element is flexibleso that an annular edge 36 normally seats upon an annular valve face 37.The annular valve face is formed upon a ring 38 which is threadedlyattached to a sleeve 39. A valve stem 40 is secured in a spider 41 whichis part of the ring 38. Upon the inhalation phase of the operation, theedge 36 lifts from the valve face due to the resiliency of the valveelement.

A head 31 is provided on the free end of the The sleeve 39 has a section42 of relatively smaller diameter and a section 43 of relatively largerdiameter joined by an intermediate section 44. The section of relativelylarger diameter is formed to provide a free sliding fit over the bead 31of the guide ring 30.

On the section of relatively smaller diameter there is provided aflexible annular seal 45 having one enlarged edge 46 confined inair-tight relationship with the section 42 by use of the ring 38 andanother edge 47 anchored in the exhalation check valve 35 by means of asnap ring 48. The exhalation check valve comprising in essence a flatannular valve seat cooperates with an annular knife edge valve element49 upon the flange 28 of the cap 11.

A second flexible annular seal 50 has one enlarged edge 51 confined inthe section 43 of larger diameter and has at the other edge an annularflat section 52 which is confined in sealed relationship between theportion 23 of the spacer 12 and the adjacent space of the flange 24 ofthe base. The two seals 45 and 56 are of loose fitting character topermit an ample degree of movement of the adjacent parts to which theyare attached.

A spring 53 contained upon a shoulder 54 in the base is pressed againstthe spider 41 and acts to urge the sleeve 33 in a direction from rightto left whereby to press the exhalation check valve seat against thevalve element 49. This is accomplished by pressure of a land 57 of thesleeve 39 against the adjacent portion of the exhaust check valve 35.

A second and lighter spring 55 bearing upon a shoulder 56 on the portion23 serves to additionally urge the exhalation check valve 35 to a valveclosed position against the valve element 49.

When in normal operation during the inhalation cycle the inflow checkvalve lifts when gas is supplied from the supply 16 to the mask. Duringthis portion of the cycle the exhalation check valve is closed. Upon theexhalation cycle, the inflow check valve 34 is forced upon its seat byair pressure from the lungs and the pressure acts against the sleeve 33,moving it in a direction from left to right. The air pressure at thesame time acts upon the exposed annular flat face of the exhalationcheck valve and overcomes tension of the spring 55 whereby to unseat theexhalation check valve and permit exhaust of gases from the lungsflowing through the device.

Should there be an inadvertent pull upon the hose tending to lengthenthe hose slightly and increase the volume of the interior hose passage,this action would tend to lower the pressure in the supply line andcause the com posite sleeve 35 to shift in a direction from left .toright, as viewed in FIGURE 1. Were it not for the presence of the spring55 and independent action of the exhalation check valve 35, this lastidentified valve would be inadvertently unseated as a result of pullupon the hose. Unseating is prevented in applicants structure by reasonof the fact that although the composite sleeve 33 is shifted in adirection from left to right when pressure in the inflow passage 16 islowered as a result of pull upon the hose, the exhalation check valveremains seated against the valve element 49 because the seal 45 isflexible whereby the spring 55 holds the exhalation check valve againstthe seat, even though the composite sleeve be moved.

Should pull continue upon the hose during several breathing cycles, thepresence of pull would have no effect upon operation of the exhalationcheck valve when the user needs to exhale because exhalation pressurewould be exercised against that portion of the exhalation check valvewithin the valve element 49 and would overcome tension of the spring 55sutficient to unseat the valve and permit exhaust gases to escapethrough the exhalation ports 26. During the inhalation cycle, while pullremains upon the hose, the inhalation check valve operates in thecustomary fashion and the spring 55 meanwhile acts to move theexhalation check valve 35 to its former seated position against thevalve element 49. Hence, regardless of what the condition may be withinthe supply passage 16, whether it be lower pressure as a result of pullupon the hose or higher pressure where such pull is released, the valves34 and 35 will continue to operate regularly and effectively even thoughthere may be a shift in position of the composite sleeve 33. Hence,pressure needed to operate both valves remains perfectly normal undersuch extraordinary circumstances and breathing continues with the samecomfort and effort as exists when there is no pull upon the hose.

Attention is directed to the diameter of the exhalation valve 49 definedby the knife-edge engagement with the face of the exhalation check valve34. This diameter establishes an area on the left-hand or exhalationside of the axially shiftable sleeve of some predetermined fixed amount.This area is responsive to exhalation pressure when the person using thedevice expels air from his lungs, at which time the inhalation checkvalve 34 is closed and comprises a portion of the area.

There is correspondingly an area on the opposite or right-hand side ofthe axially shiftable sleeve which is responsive to pressure in thesupply passage 16 connected as shown to the hose 15. The effective areaon the last mentioned side of the axially shiftable sleeve is the areaencompassed within the circumference of the apex of the flexible annularseal 50. This being a flexible element, something less than the entirebreadth of the seal is responsive in full to the supply pressure and itis clear that one half of the breadth of the seal is thus responsive,this being the half located diametrically inwardly with respect to theapex. Since the circumference at the apex of the flexible annular seal50 is obviously very much greater than the circumference at the point ofthe knife edge of the exhalation valve seat, it is obvious that ifpressures on opposite sides of the axially shiftable sleeve were thesame, then the area on the right side being greater, the sum totalpressure on that side would be greater and the sleeve would tend to movefrom right to left.

When there is a depletion of oxygen in the supply line, a new conditionprevails. Initially when inhalation is taking place, the inhalationcheck valve 34 is lifted from its seat and a negative pressure inducedby the inhalation effort is set up and becomes the same on both sides ofthe check valve because the valve is open. In other words, when the userinhales and thus reduces the pressure in the mask, he simultaneouslyreduces the pressure by the same amount on the right-hand side or supplyside of the axially shiftable seal which is in effect the exhalationvalve. Thereafter during the normal inhalation cycle when the negativepressure induced is less than that created initially the forces actingon the valve element will react in a direction causing the exhalationvalve to open and stay open until the negative pressure is broken on thesupply side. This occurs because the area on the right-hand side wherethe greater negative pressure exists is greater than the area on themask side Where the lesser negative pressure prevails. By way ofexplanation it should be noted that if the areas were the same therewould be a balance of forces on opposite sides and the exhalation valvewould remain seated. The reaction is in essence the reverse of thereaction which would occur if the pressures were positive pressures. Theunseating condition described converts the exhalation valve into anambient air port so that the subject can inhale ambient air and. hencesuffocation is prevented. The phenomena is particularly etfective due tothe hose pull protection feature embodied in the movable character ofthe exhalation check valve 35 relative to the axially shiftable sleeve.With the proper design of the hose pull protection seal 45, thesensitivity of this anti-suffocation feature can be controlled and thelevel of suction required to provide anti-suffocation can be controlledby both the differential areas and the resistance across the hose pullprotection seal.

Moreover, from the type of construction herein described it will beunderstood that the base and cap can be separated from each other veryreadily by removal of the screws 27, in which event the spacer can alsobe removed and together with it all portions of the composite sleeve 33.The last identified sleeve carrying all moving parts with it can readilybe replaced if need be with a new composite sleeve without anyreadjustment being necessary and the sleeve mentioned after removal canbe serviced or repaired at a location equipped especially with tools andjigs for that purpose.

In another form of the invention shown in FIGURE 3, there is providedalso a combination inhalation-exhalation valve device including theanti-suffocation feature but including also sundry refinements. In thisform there is a valve body indicated generally by the referencecharacter 60 and consisting of a mask end element 61 and a hose endelement 62. These elements are joined together through a spacer 63 bymeans of screws 64. The spacer contains one or more openings or ports 65which comprise the exhalation port means. In the mask end element is asupply passage 66 which is supplied by gas from the passage 67 in a hose68 in order to pass the gas into the interior of the valve devicethrough a passage indicated generally by the reference character 69.Within and forming in part the passage 69 is a tubular assembly 76)which consists essentially of an outer sleeve 71 and an inner sleeve 72,having reference to the relative diameters of the sleeves. The outersleeve extends partially into an annular pocket 73 formed in the hoseend element 62, the pocket having an outer edge 74 and an inner edge 75.To properly secure the sleeve, namely, the outer sleeve 71 in theposition shown in FIGURE 3, there is provided a ring 76 of flexiblematerial, annular in shape, and including a bead 77 at its outerextremity secured to the outer edge 74. A somewhat similar bead 78 atits inner extremity is secured to the inner edge 75 by employment of aretaining ring 79. The ring 76 essentially closes the pocket 73 exceptfor the provision of a vent passage 80 which communications between thepocket 73 and the supply passage 66.

The ring 76 is connected by another retaining ring 81 to the innersleeve 71 at its outer face and adjacent the end which is receivedwithin the pocket 73. From this description it will be clear that theouter sleeve 71 is essentially centered as well as supported by thedouble folds of the ring 76 in a fashion which is capable of guiding thesleeve during movement and also holding it properly in place. The innersleeve 72 is connected to the outer sleeve throughout a sealed joint 83of some appropriate conventional design which makes the eal tight andalso which makes the sleeves rigid with respect to each other. At theleft end of the inner sleeve 72 is a spider 84 providing a central area85 by means of which a valve stem 86 is retained, thereby to attach aninhalation check valve 87 in position. A rim 88 of the inhalation checkvalve seats upon an annular seat 89 so that upon inhalation when theinhalation check valve 87 is lifted from its seat, air or oxygen willflow into a com bined inhalation-exhalation chamber 90 and thus beavailable for breathing.

A spool spring 91 seated on a shoulder 92 on the hose end element 62 andupon a similar shoulder 93 in the inside sleeve 72 normally tends tourge the tubular assembly endwise in a direction from right to left sothat a valve face or valve face element 94- is seated upon an exhalationvalve seat 95.

It will be noted in the form of invention of FIGURE 3, similar to theform of invention of FIGURES 1 and 2, the exhalation valve seat 95defined by the knife edge circumscribes an area on the tubular assemblywhich is subject to exhalation pressure. There is also an area on theopposite side of the tubular assembly subject to pressure in the supplyline. The pressure acts in part directly upon the tubular assembly andalso through the vent passage 80 into the pocket 73 and there againstportions of the tubular assembly. The efiective area subject to supplyline pressure is circumscribed by the apex of a loop 96 forming part ofthe ring 76, the loop 96 being exterior with respect to the outsidesleeve 71. An inside loop 77 is likewise subject to the same pressurebut entirely throughout its available area. Moreover, the areacircumscribed by the apex of the loop 96 is greater than the areacircumscribed by the exhalation valve seat. Hence, there is a greaterarea on the right side or supply side of the tubular assembly subject togas pressure than the area on the opposite side or mask side.

In this embodiment also under circumstances where there might be afailure of supply when the subject inhales, pressure on the mask sidewill be reduced. Simultaneously pressure will be reduced to a negativepressure of the same amount upon the opposite side or supply side of thetubular assembly. Since the area on the latter side is greater than thearea on the mask side, the forces acting on the tubular assembly as avalve member will react as previously described in a direction causingthe exhalation valve to open, thus converting the exhalation valve intoan ambient air port, converting the valve device into an antisulfocationvalve. This is because the exhalation valve will remain open under thosespecial circumstances and permit the subject to breathe ambient air,thus to fill his lungs with a complete tidal volume, even though theremay be a shortage of oxygen at the supply.

In operation otherwise, when the subject inhales, the inhalation checkvalve 87 will be lifted and thus permit oxygen to pass into the combinedinhalation-exhalation chamber and thus be available for breathing.During this portion of the cycle the spring 91 acting in the directionshown will move the tubular assembly and cause the valve face orexhalation valve element 94 to seat upon the seat 95. When thereafterthe subject exhales, the inhalation check valve is closed and pressureupon the respective side of the tubular assembly overcomes pressure ofthe spring 91 and the supply pressure, causing the tubular assembly toshift from left to right, opening the exhalation valve so that thesubject can exhale. This movement is cushioned by the necessity of gastrapped within the pocket 73 to pass out of the pocket through therestricted vent 80. The vent is restricted to slightly retard movementof the tubular assembly, although not to hinder it objectionably. Thisdamping action of the vent coupled with the multiple flexible mountingof the sleeve 71 assures a smoothness in the reciprocating action of thesleeve. It accordingly prevents chatter and particularly is effectivewhen there might be a rapid breathing by the subject under particularcircumstances where a clatter or rattle might be objectionable.Moreover, constructed as shown the fabrication of the parts can besimplified and improved. Grinding and lapping of the valve face 94 ismade particularly easy before the inner sleeve 72 has been applied.Attachment of the ring 76 is a simple operation by employment of theretaining ring 81 as is also attachment by employment of the retainingring 79 during initial assembly stages. Attachment of the bead 77 at theouter extremity can be readily made by first impressing the bead into anappropriate annular recess 98 by hand and thereafter firmly anchoring itin place merely by assembling the mask end element and hose end elementupon the spacer 63. As shown and described, the parts are rugged and byvirtue of the design need not be held to difiicult tolerances but at thesame time provide a dependable valve having the improved safety featuresherein set forth.

While the invention has herein been shown and described what isconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of theinvention, which is not to be limited to the details disclosed hereinbut is to be accorded the full scope of the claims so as to embrace anyand all equivalent devices.

Having described the invention, what is claimed as new in support ofLetters Patent is:

1. A composite inhalation-exhalation valve device with low pressureprotection comprising a valve body having a passage therethrough and asupply connection thereon for a supply hose in communication with saidpassage, a sleeve within said passage and movable axially relative tothe passage, and a flexible connection between the exterior of thesleeve and the body, an inhalation valve pas sage at one end of thesleeve forming a communication between the end of the passagewayadjacent the supply connection and the opposite end, said sleeve on thesupply side thereof having a first area responsive to pressure in thesupply passage of a predetermined amount, and an inhalation check valveelement normally closing said passage, a first annular exhalation valvecomponent on said body, exhalation passage means forming an exhalationport through the body adjacent said exhalation valve component, a secondexhalation valve component mounted on the sleeve, one of said componentscomprising an exhalation valve element and the other of said componentscomprising an exhalation valve seat, said exhalation valve seat at theline of engagement with the exhalation valve element defining a secondarea responsive to exhalation pressure, said second area being of lesseramount than said first area whereby to increase the effective totalpressure on said first area during the inhalation cycle thereby toinhibit suffocation when the supply hose is no longer capable ofsupplying the valve device.

2. A composite inhalation-exhalation valve device with 0 low pressureprotection comprising a valve body having a' passage therethrough and asupply connection thereon for a supply hose in communication with saidpassage, a sleeve within said passage and movable axially relative tothe passage, and a flexible connection between the exterior of thesleeve and the body, an inhalation valve passage at one end of thesleeve forming a communication between the end of the passagewayadjacent the supply connection and the opposite end, said sleeve on thesupply side thereof having a first area responsive to pressure in thesupply passage of a predetermined amount, and an inhalation check valveelement normally closing said passage, a first exhalation valvecomponent on said body, exhalation passage means forming an exhalationport through the body adjacent said exhalation valve component, a secondexhalation valve component mounted on the sleeve and a flexibleconnection between said second exhalation valve component and thesleeve, one of said components comprising an exhalation valve elementand the other of said components comprising an exhalation valve seat,said exhalation valve seat at the line of engagement with the exhalationvalve element defining a second area responsive to exhalation pressure,said second area being of lesser amount than said first area wherebysubsequent to depletion of supply to decrease the etfective totalpressure on said first area during the inhalation cycle thereby toinhibit suffocation, and resilient means acting between the body and theexhala- 8 tion valve element normally urging said exhalation valveelement to a seated position whereby to enable movement of the sleeve ina direction toward the supply connection unaccompanied by movement ofthe exhalation valve away from seated position.

3. A composite inhalation-exhalation valve device comprising a valvebody having a passage therethrough and a supply connection thereon, atubular assembly within said passage movable axially relative to thepassage, said assembly comprising an outer sleeve and an inner sleevejoined together at adjacent ends with a sealed joint, said bodycomprising a spacer having an exhalation port therein, a mask endelement and a hose end element releasably joined together and to saidspacer, said mask end element having an annular exhalation valve seatthereon, an annular exhalation valve element on said outer sleevemovable to seated and unseated positions relative to said seat, saidsupply end element having an annular pocket adjacent said outer sleeveadapted to receive said outer sleeve when the valve element is inunseated position, and a restricting vent passage between the pocket andthe passage at the supply end thereof, an annular flexible connectionbetween said outer sleeve and said supply end element comprising a ringof sheet material having an inner edge connected to the mask end elementat an inside edge of the pocket, an outer edge connected to the mask endelement at the outer edge of the pocket and a mid-portion connected tosaid outer sleeve whereby to provide a plurality of fiexure connectionsbetween the outer sleeve and the body, an inhalation check valve passagein said inner sleeve between the supply end element and the mask endelement and an inhalation check valve operably mounted on said seat,resilient means acting between said body and said tubular assemblynormally urging said exhalation valve element to seated position, saidtubular assembly having an area on the supply side subject to a negativepressure upon depletion of the supply greater than an area on the maskside thereof defined by said exhalation valve when subject to acomparable negative pressure whereby to inhibit suffocation.

References Cited in the file of this patent UNITED STATES PATENTS2,820,469 Seeler Jan. 21, 1958 2,936,779 Kindred May 17, 1960 2,954,793Se'eler Oct. 4, 1960 FOREIGN PATENTS 1,105,803 France July 6, 1955 OTHERREFERENCES New Valve for Non-Rebreathing Systems, M. Jack Frumin et al.,Anesthesiology, vol. 20, No. 3, May-June 1959, pp. 383-385. (A copy ofthis publication is found in the Washington, DC. libraries of thefollowing institutions: National Library of Medicine and National 111-stitution of Health.)

1. A COMPOSITE INHALATION-EXHALATION VALVE DEVICE WITH LOW PRESSUREPROTECTION COMPRISING A VALVE BODY HAVING A PASSAGE THERETHROUGH AND ASUPPLY CONNECTED THEREON FOR A SUPPLY HOSE IN COMMUNICATION WITH SAIDPASSAGE. A SLEEVE WITHIN SAID PASSAGE AND MOVABLE AXIALLY RELATIVE TOTHE PASSAGE, AND A FLEXIBLE CONNECTION BETWEEN THE EXTERIOR OF THESLEEVE AND THE BODY, AN INHALATION VALVE PASSAGE TO ONE END OF THESLEEVE FORMING A COMMUNICATION BETWEEN THE END OF THE PASSAGEWAYADJACENT THE SUPPLY CONNECTION AND THE OPPOSITE END, SAID SLEEVE ON THESUPPLY SIDE THEREOF HAVING A FIRST AREA RESPONSIVE TO PRESSURE IN THESUPPLY PASSAGE OF A PREDETERMINED AMOUNT, AND AN INHALATION CHECK VALVEELEMENT NORMALLY CLOSING SAID PASSAGE, A FIRST ANNULAR EXHALATION VALVECOMPONENT ON SAID BODY, EXHALATION PASSAGE MEANS FORMING AN EXHALATIONPORT THROUGH THE BODY ADJACENT SAID EXHALATION VALVE COMPONENT, A SECONDEXHALATION VALVE COMPONENT MOUNTED ON THE SLEEVE, ONE OF SAID COMPONENTSCOMPRISING AN EXHALATION VALVE ELEMENT AND THE OTHER OF SAID COMPONENTSCOMPRISING AN EXHALATION VALVE SEAT, SAID EXHALATION VALVE SEAT AT THELINE OF ENGAGEMENT WITH THE EXHALATION VALVE ELEMENT DEFINING A SECONDAREA RESPONSIVE TO EXHALATION PRESSURE, SAID SECOND AREA BEING OF LESSERAMOUNT THAN SAID FIRST AREA WHEREBY TO INCREASE THE EFFECTIVE TOTALPRESSURE ON SAID FIRST AREA DURING THE INHALATION CYCLE THEREBY TOINHIBIT SUFFOCATION WHEN THE SUPPLY HOSE IS NO LONGER CAPABLE OFSUPPLYING THE VALVE DEVICE.